Just a reminder:
Every time you modify your spec file, please
- change the release number to avoid confusion
- add proper %changelog entry
- post the URLs of new srpm / spec on the review request bug
( please post ! )
Otherwise no one will notice you did some work after (potential)
reviewer added a comment.

For -2:
* Unused macro / consistent macro usage
- %ruby_sitelib macro seems to be used no where.
- %geminstdir should also be used also in %check.
* The place of documents
- I don't see any reason you should move README.markdown or
so to under %{_defaultdocdir}
* Documents
- CONTRIBUTORS, Rakefile files should be marked as %doc.
- spec/ test/ directories should also be marked as %doc.